Core catcher



A. C. CATLAND ET AL Dec. 28, 1937.

' coRE cATcHER.

Filed 0G12. 13, 1936 y asheets-sheet 1 1, Dec. 28, 1937. A Q CTLAND Er AL 2,103,611

CORE CATCHER Filed Oct. 13, 1936 2 Sheets-Sheet 2 Patented Dec. 2s, 1937 PATENT OFFICE CORE CATCHEB Alfred G Catland, Alhambra, and Philip C. Efromsom Whittier, Calif., assignors to Globe lrlliil Tools Company, Los Nietosf Calif., a corl A'poration of California Application October 13,

' 1o claims.

This invention relates towell drilling tools and relates more particularly to a core catcher for use in a rotary corejdrill. A general object of the invention is to 4Ifgro'vi'de a practical, effective and very dependable core catcher.

Another object of ythe'invention is to provide acore catcher embodying slips for, gripping the core and pivoted'dogs for assisting in gripping the core and for relieving the strain on the slip carrying springs when the Acore catcher is actuated. l

Another object of this invention' is to provide a core catcher'enibodying a slip ring or body presenting tapered surfaces vfor actuating the slips and vcarryingUpivoted corel gripping dogs that operate Ato hold, the body-against turning and undesirable vmovement, thereby reducing the strains on the 'springs which carry the slips.

Another object pf the invention is to provide a core catcher of the character mentioned in which the provision or inclusion lof the core grip-A ping dogs does-not complicate the construction 'or require theje'nlargement of the core catcher body.

Another object of this invention is to provide a core catcher of the character mentioned in which the pivoted dogs are positive and dependable in gripping and supporting the core and are capable of dependably gripping cores of various earth formations. f

A further object `of the invention isto provide a corev catcher of the character mentioned that does not foul the core, score the core, Aor otherwise injure the core during the drilling operation.

The various Aobjects and features of our invention will be fully understood from the follow- 'ing detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a vertical detailed sectional view of the lower portion of a core drill illustrating the core catcher of the present invention in the operative position in the drill. Fig. 2 is a, transverse detailed sectional view taken as indicated by line 2--2 on Fig. 1. Fig. 3 is afragmentary, enlarged, vertical, detailed sectional view of the core catcher within the drill and Fig. 4 is a transverse detailed sectional view, of the core catcher taken as indicated by line 4-4 on Fig. 3.

The core catcher of the present invention is suited for use in core drills .of various types and V 1936, Serial N0.105,3'l0

(Cl. Z55-72) derstood-that the invention is not to be construed as limited or restricted to the specific form Aor application of the invention illustrated.

Thecore drill illustratedin the drawings includes an outer barrel I adapted to be connected with the lower end of a rotary drilling string. A special sub I I is threaded on the lower end of the outer barrel I0. The sub .II extends a considerable distance below the outer barrel I0 and has a relatively large internal diameter.l A bit .hea'd I2 is screwthreaded on the lower end of the sub I I'. Circumferentially spaced recesses I3 and I4 are provided in thelower end of the bit head I2 to receive roller cutters I5 and I6, respectively. The roller cutters I5 and I6 are rotatably supported on pins I5*a and IISa extending across the recesses I3 and I4; The central vertical openings I'I in the tubular bit head I2 is adaptedto freely receive the core cut or formed by the cutters I5 and I6. An annular recess I8 is provided within the bit head I2.

'I'he core drillfurther includes a tube or sleeve I9 which seats downwardly in the recess I8 0f the head I2 and which lextends upwardlythrough the sub II. The sleeve I9 is spaced from fluid passage 20. Ports 2| in the bit head I2 conduct the circulation fluid downwardly from the passage 20 to the recesses I3 and I4 to flush the cutters I5 and I6. A flat annular upwardly facing shoulder 22 is provided on the interior of the sleeve I 9. A tapered annular shoulder 23 occurs on the interior of the sleeve I9 abovethe shoulder 22. The sleeve I9 is tapered or ilared outwardly adjacent its upper end. f The core A `the interior of the sub II vleaving an annular drill includes an inner barrel 24 arrangedlongitudinally in the outer barrel I0 to receive the core. A bearing collar 25 is xed to the lower end of the inner barrel 24. A shoulder 26 on the collar 25 is adapted to bear downwardly against the upper end of the sleeve I9 and the collar carries a hardened bearing ring 21 for bearing upwardly against a shoulder 28 on the interior of the sub II. The inner barrel 24, supported as just described, is free to float, that is, it may turn or remain stationary at will. The sleeve I9 is also floating so that it may remain stationary during rotation of the drill. Ports 30 are provided in the collar 25 to connect the pas-v The core catcher of the present invention includes, generally, what we will term a body 32, pivoted core gripping dogs 33 on the body 32, a ring 34 below the body 32, slips 35 connected ,through the tubular or annular body 32 freely .f

tion with the body 32, and springs 36 on the ring 34 for cooperating with the core to control the slips 35.

The body 32 is provided tocarry the dogs 33 and to present tapered abutments for actuating the slips 35. The body 3 2 is a tubular element arranged within the sleeve I9 of the drill. In the preferred construction the body 32 is sectional comprising two telescopically arranged rings A and B. The ring A forms the upper portion of the body 32 and has a flat upper end adapted to cooperate with the lower end of the collar 25 to limitf the upward movement of the body 32. The ring A fits in the sleeve I9 for free longitudinal and turning movement. The upper portion of the ring A may be flared outwardly to fit within the correspondingly ilared portion of the sleeve I9. An internal annular recess 31 extends upwardly in the ring A from its lower end. 'I'he recess 31 may have a ilat upper wall and a cylindrically curved side'wall. Notches or openings 38 are provided in the lower end of the body ring A. The openings 38 are circumferentially spaced and have .communication with the recess 31. The upper portion of the body ring A is shaped or formed to receive the slips 35. Circumferentially spaced longitudinal slots 39 are provided in the upper portion of the body ring A to receive the slips 35. 'Ihe slots 39 extend downwardly from the upper end of the body ring A to the recess 31. The side walls of the slots 39 may be flat and parallel while the bottom or inner walls 40 of the slots are inclined downwardly and inwardly relative to the vertical axis' of the drill. 'Ihe slot walls 49 form inclined abutments for the slips 35.

The body ring B nests in the lower portion of the ring A fitting upwardly in the recess 31. The ring B- is generally cylindrical both inside and outside and has ilat ends. The lower end of the body ring B is adapted to cooperate with the shoulder 22 to limit the downward movement of the body 32. 'I'he body 32 is proportioned to have limited vertical or longitudinal movement in the sleeve I9. An annular external groove 4I is provided in the body ring B. 'Ihe outer side of the groove 4I is closed by the lower wall portion of the ring A. Rivets 42 are provided In vertically and circumferentialiy spaced openings in the telescoping portions of the rings A and B to connect the rings. The lower rivets 42 may pass radially through the -groove- 4I. Circumferentially spaced openings 43 are provided in the wall of the ring B. The openings 43 are vertically elongate'and extend downwardly from the upper end of the ring B. The parts are related so that the` openings 43 are vertically aligned with the openings 38 and their lower ends communicate with the openings 38. The communicating openings 38 and 43 lie in vertical planesspaced between the vertical planes of the slots 39. The upper inner corner of the body ring B may be bevelled 0E to be flush with the inclined walls 48 of the slots 39. The lower end of the body ring A clears the inclined shoulder 23 when the lower end of the ring B is in cooperation with the shoulder 22. The opening receives or passes the core.

33 also operate to prevent undesirable relative movement between the body 32 and the ring 34 thus relieving the strains on the spring meml cores or rock cores.

bers connecting the slips 35 with the ring 34. The dogs 33 are solid tooth-like parts having pointed or tapered active ends to bite into the core. In the structure Iillustrated the dogs 33 are pivotally mounted in the openings 43 in the body ring B to have their outer portions project into the openings 38 in the body ring A.

Pivot pins 44 pass through openings in the dogs 33 and have their opposite ends supported in the groove 4I to pivotally support the dogs. Notches 45 are provided in the outer portions oftheA dogs 33 to receive torsional springs or spring wires 46. 'I'he spring wires 46 each have an end bearing on a wall of the recess 31 and an end bearing on a dog 33 to urge the dog against the core. Cams 41a may be provided on the projecting outer portions vof the dogs 33 to cooperate with the shoulder 23 and assist in pivoting the dogs downwardly and inwardly into the core when the core catcher is actuated. \The lower walls of the openings 43 form abutments to limit the downward pivoting of the dogs 33 and to assist in supporting the load carried by the dogs. Fig.

1 illustrates the dogs 33 in cooperation with the lower Walls of ,the openings 43. The active or biting ends ofthe dogs 33 are received in the openings 43 when the core extends through the body 32 so that the dogs do not interfere with the core.

In accordance with the invention the dogs 33 are of different lengths. Certain of the dogs 33 are relatively long 'to bite into soft and undersized cores, certain of the dogs are of medium length to bite into medium hard cores and certain of the dogs are relatively short to grip hard The dogs 33 are preferably equally spaced about the interior of the body 32 as illustrated throughout the drawings.

' IIhe ring 34 may be a simple integral member and is arranged in the sleeve I9 below the The slips 35 are Wedge-like gripping partsb voperable in the slots 39. The back sides or surfaces 41 of the slips 35 are inclined downwardly and inwardly'to slidablycooperate with the walls 46 of the slots 39. The active inner surfaces of' the slips 35 are curved to conform, generally, to the core and have horizontal wickers or teeth 48 for gripping the core. The slips 35 are connected with the free ring 34 to operate in unison and to be controlled by cooperation of springs 36 with the core. Springs 49 connect the slips 35 with the ring 34. .The springs 49 are secured to the interior of the ring 34 by rivets 59. The upper vportions of the springs v49 are secured to the back sides of the slips 35 by rivets 5I or the like. The springs 49 are preferably recessed or countersunk in the inclined surfaces 41 of the slips. The springs 49 extend vertically through the body ring B and the slots 39. The parts are related so that the springs 49 are spaced between the spaced dOgS 33. 1

I'he springs 36 are provided to have movement resisting cooperation with the core when the drill is raised so that the slips 35 are actuated inwardly by, the upwardly moving inclined surfaces or walls 40. 'I'he springs 36- are in thenature of leaf springs or spring amis secured to the ring 34 to project upwardly and inwardly from its interior. In practice the springs 36 may be secured to the ring 34 by the rivets 50. The upper portions of the springs 36 may be bent inwardly to more effectively engage the core. The springs 36 are sufficiently flexible to yield or ilexoutwardly when the core -is received in the drill so that they do not interfere with or injure the core.` As the body 3-2 andthe ring 34 may remain nonrotatable during the drilling operation the springs 36 do not turnduring the drilling and, therefore,- vdo not score the core. v

During the vdrilling operation the cutters l5 and t6 make an annular cut in the earth formation leaving a core'whlch is received in the drill. The core is adapted to extend upwardly through the body 32 to be received inthe inner barrel 24. The engagement of the springs 36 with the core holds the ring 34 in a position Where theslips 35 are retracted in the upper portions of the slots A, 39. The springs 36 engaging the core also resistl ring 34 and the slips or prevent turning of the 35 connectedwith the ring. The spring urged dogs 33 engage the core'to resist turning of the body 32 relative to the core. Thus the ring 34,

the slips 35 and the body 32 may remain nonrotatable during the drilling operation. The dogs drill is raised to .actuate the core catcher.

33 urged against the core by the spring wires 46 prevent or tend to prevent turning of the body 32 so that the springs 49 are subjected to little or no torsional stress.. 1

I'After a core of sufcient length has been cut When the drill is raised the engagement of the shoulder 22 with the lower end of the body ring B causes the body 32 to move upwardly with the drill. The springs 36 bearing against the core hold the ring 34 against upward movement and hold the slips r3,5 vagainst upward movement. `Accordingly, upward movement of the body 32 resultsin active cooperation of the slot walls 40` with the rear surfaces 41 of the slips 35. The inclined walls 40 cooperating with the surfaces il force the slips 35 inwardly into gripping engagement with the core. During this actuation of the slips the spring urged dogs 33 individually pivot downwardly and inwardly into biting engagement with the core. In practice the vertical movement of the body 32 necessary` to actuate the slips 35 effects the proper actuat1on of the pivoted dogs 33. During the pivotal movement of the dogs 33 from substantially vertical positions to the positlonsillustrated-in Fig. 1 of the drawings the body 32- maybe moved .vertically to effect the completeinward actuation oi the slips 35. Thus the slips l35 and the dogs 33 simultaneously vobtain firm grippingy engagement with the core. n Further upward` movement of the drill results in breaking free. of -the core from the earth formation. The core is recover diI from the well in the drill. The slips 35 and he dogs 33 serve to dependably support the core yinthe drill as the drill is withdrawn from the well.

Having described only a typical preferred form and application of our invention, we do not w1sh to be limited or restricted to the specic details herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described our invention, we claim:

l. A core catcher for use in a tubular well drill including, an annular body for arrangement in the drill to move vertically therewith, a free ring below the body, slips connected with the ring and actuated into gripping engagement with the core by cooperation with the body, and pivoted coregripping dogs on the body. f

2. A core catcher for use in a tubularwell drill including, an annular body for arrangement in the drill to move vertically therewith, a free ring below the body, slips connected with the ring and actuated into gripping engagementwith the core by cooperation with Athe body, means on the ring cooperable with the core to resist movement of the ring, and pivoted dogs on the body cooperable with the core to prevent undesirablemovcment of the body and t'o grip the core.

3. A core catcher for use in a 'tubular well drill including, an annular body for arrangement in the ,drill to move vertically therewith, a free ring below the body, slipsv connected with the ring and actuated into gripping engagement with the core by cooperation with the body, and spring urged dogs on the body engaging the core to prevent relative turning between the body and ring.

4. A core catcher foruse in a tubular well drill including, an annular body for arrangement in the drill to move vertically therewith, a free ring below the body, slips connected with the ring and actuated into gripping engagement with the coreby cooperation with the body, means on the ring, and means on the body for engaging the- 'core to resist turning of the body, the last mentioned means including dogs pivoted on the body, and means urging the dogs against the core.

6. A core catcher for use in a rotary core drill including, a floating tubular body in the drill capable of free turning and limited vertical movement, the body having inclined slots. a floating l ring -belowthe body, slips in the slots operable inwardlir by their inclined walls, spring members connecting the slips with the ring to move therevwith,means on the ring engageable with the core to resist movement of the ring, and spring urged dogs on the body for gripping the cor'e.

7. A. core catcher for use in a rotary core drill. including, a iloating tubular body in the drill capable of free turning and limited vertical movement, the body having inclined slots, a floating ring below the body, slips in the slots operable inwardly by their inclined walls, spring members connecting the slips with the ring to move therewith, means on the ring engageable with the core to resist movement of the ring, and spring -urged dogs of diii'erent lengths on the body for gripping v the COTE.

A` core catcher for use in a rotary core drill including, a floating tubular body in the drill capable of free turning and limited vertical movement, the body having'circumferentially spaced inclined slots, a floating ring below the body,

slips in the slotsoperable inwardly by their inclined walls, spring members connecting the slips with the ring to move therewith, means on the ring engageable with the core to resist movement of the'- ring, and pivoted dogs on the body spaced between thejspring members and operable tov grip lthe core. .I

9. A core-catcher for use in a rotary core drill including, a floating tubular body in the drill capable of free turning and limited vertical movement, the body having circumferentially spaced inclined slots, a. `oating ring below the body, y I

1o opening of a core drill comprising, a. tubular body arranged in the opening to move vertically with the drill, a. shiftable member in the opening below the body, slips connected with the member and actuated into gripping engagement with the core by cooperation with the body upon upward movement of the body with the drill, and pivoted core gripping dogs on the member.

ALFRED C. CATLAND.

v PHILIP C. EFROMSON. 10 

